Rowing machine



FIG. 1 is a perspective view;

FIG. 2 is a right side view;

FIG. 3 is a left side view;

FIG. 4 is a top view;

FIG. 5 is a bottom view;

FIG. 6 is an enlarged front view; and,

FIG. 7 is an enlarged rear view. 

The ornamental design for a rowing machine, as shown and desribed. 